Yeah I agree, it's a good compromise and I definitely use MicroG despite that (though not on Calyx but Lineage for MicroG, as I don't have a Pixel phone). I think the Calyx precautions are more than adequate. And better than Lineage's.

I just wanted to highlight the difference in focus, GrapheneOS will always pick the security side when a compromise needs to be made. Another example is the "We don't lie about security features" stance about SafetyNet. Even though a GrapheneOS phone is arguably more secure than a random manufacturer-modified Android rom. I agree that signature spoofing has an unnecessarily bad name. Probably because some mainstream roms like Lineage eschewing it. Personally I think it's a great tradeoff between privacy and functionality.